We present a probabilistic analysis on conditions of the exact recovery of block-sparse signals whose nonzero elements appear in fixed blocks. We mainly derive a simple lower bound on the necessary number of Gaussian measurements for exact recovery of such block-sparse signals via the mixed 𝑙 2/𝑙𝑞 (0 < 𝑞 ≤ 1) norm minimization method. In addition, we present numerical examples to partially support the correctness of the theoretical results. The obtained results extend those known for the standard 𝑙𝑞 minimization and the mixed 𝑙2 /𝑙1 minimization methods to the mixed 𝑙2/𝑙𝑞 (0 < 𝑞 ≤ 1) minimization method in the context of block-sparse signal recovery.